<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script src="https://unpkg.com/vue@next"></script>
<div id="app">
    <ul v-for="arr in numSets">
        <li v-for="item in evenNum(arr)">{{item}}</li>
    </ul>

</div>
<script>
    const vueOpt = {
        data(){
            return {
                numSets: [[1, 2, 3, 4, 5, 6], [7,8,9,10, 11, 12]]
            }
        },
        methods:{
            evenNum(nums){
                return nums.filter(value=>value%2 === 0)
            }
        }
    }

    Vue.createApp(vueOpt).mount('#app');
</script>
</body>
</html>
